Lamp socket



D. W. HARLING Feb. 7, 1967 LAMP SOCKET Filed Oct. 23, 1964 United StatesPatent 3,303,456 LAMP SOCKET Donald W. Harling, Milwaukee, Wis, assignorto McGraw-Edison Company, Milwaukee, Wis., a corporation of DelawareFiled Get. 23, 1964, Ser. No. 405,970 7 Claims. (Cl. 339--180) Thisinvention relates to lamp sockets and, more particularly, to new andimproved lamp sockets having particular, but not exclusive, applicationto outdoor lighting fixtures.

One type of luminaire employed for street or area lighting has anelongated, open-bottomed housing provided with a bottom closure memberand which carries a sealed optical assembly and electrical components,such as ballasts and capacitors required for operating metallicvapor-type lamps. The optical assemblies of such luminaires generallyinclude a refractor and a reflector which are releasably mounted on thehousing or the bottom closure member so that when the bottom closurememher is pivoted to an open position, the optical assembly may beremoved for cleaning and relamping. In order to minimize the hazards ofsuch relamping operations, the bottom closure member of some prior artlurninaires carry disconnect contacts which open-circuit the lamp socketwhen the bottom closure member is pivoted to an open position.

Prior art luminaire lamp sockets were not wholly satisfactory becausethe lineman was not always able to readily determine if good con-tacthad been obtained between the lamp and the lamp socket terminals after alamp replacement had been made since the socket was usually de-energizedwhen the luminaire was open for servicing. Certain other prior art lampsockets were unsatisfactory because they were not able to prevent thelamp from shaking loose so that contact between the lamp and socketcontacts was sometimes broken as a result of vibration caused by windand trafiic. Other lamp sockets were provided with shakeproof deviceswhich required tools for the removal of lamps thereby greatlycomplicating maintenance operations.

It is an object of the invention to provide a new and improvedlampholder for luminaires employed for street or area lighting.

Another object of the invention is to provide a lampholder whereinvisual observation can be made of the engagement between the lamp andthe lampholder terminals.

A further object of the invention is to provide a lampholder withlamplocking means which does not require tools or other appliances forrelease when relamping is required.

Yet another object of the invention is to provide an economicallampholder wherein relamping is greatly facilitated.

These and other objects and advantages of the instant invention willbecome more apparent from the detailed description thereof taken withthe accompanying drawings wherein:

FIG. 1 is a side elevational view, partly in section, of a lumin-aireemploying the lamp socket according to the instant invention;

FIG. 2 is a view taken along lines 22 of FIG. 1;

FIG. 3 is a top plan view of the lampholder according to the instantinvention;

FIG. 4 is a view taken along lines 44 of FIG. 3; and

FIG. 5 is a view taken along lines 55 of FIG. 3.

Referring now to the drawings in greater detail, FIG. 1 shows an outdoortype luminaire provided with an elongate open-bottomed housing 11 havinga portion 12 integrally formed on one side and which encloses means3,333,455 Patented Feb. 7, 1967 (not shown) for attaching the luminaireto a pole or other vertically extending structure (not shown).

The luminaire 10 also includes an optical assembly 13 disposed in theother end of housing 11 and comprising a generally inverted, ovatereflector 14 for reflecting light rays in a generally downwarddirection, as viewed in FIG. 1, and a cooperating refractor 15 forfurther modifying the downwardly directed light rays into the desiredlight pattern. The optical assembly 13 is mounted on a bottom closuremember 17 which is supported at one end beneath the housing portion 12by a hinge assembly 19 to permit movement in a counterclockwisedirection as shown by phantom lines in FIG. 1, so that the opticalassembly and other electrical components may be exposed for servicing. Aquick release latch assembly 20 is provided at the opposite side of theclosure member 17, so that the latter may be latched in its closedposition shown by full lines in FIG. 1, whereby the optical assembly 13is in its operative position.

A lamp socket 21, according to the instant invention, is mounted on thereflector 14 and extends through an opening 22 on the upper end thereoffor supporting a lamp 24 within the optical assembly 13.

In order to tie-energize the electrical components of the luminaire 10,such as the lamp 24 and the ballast 25, when the bottom closure portion17 is open, connection to these components is made through disconnectcontacts 26 having a fixed portion carried by a first terminal block 27mounted on the housing 11 and a movable portion carried by a secondterminal block 28 mounted on the bottom closure member 17. Thus, whenthe bottom closure member 17 is opened, the contacts 26 disengage toopen circuit the various electrical components so that there is no riskof exposure to electrically live parts when the luminaire is beingserviced.

As seen in FIGS. 1 and 2, the refractor 15 is an inverted, bowl-shapedmember having an outwardly extending flange 30 formed circumferentiallyaround its outer peripheral edge for engaging the margin of a circularopening 33 formed in the bottom closure member 17. The lower peripheralend of the reflector 14 is coextensive with the flange 30 and thereflector 15 and has an outwardly extending flange 35 for cooperativeengagement therewith.

The flange 30 of the refractor 15 is resiliently held in engagement withthe margin of the opening 33 in the bottom closure member 17 by a pairof elongate flat springs 38 which are mounted on the opposite sides ofthe bottom closure member 17, as seen in FIG. 2. The reflector 14 isresiliently held in engagement with the refractor 15 by a pair ofelongate coil springs 42 which are anchored at their lower ends to theflat springs 38 and at their upper ends to the lampholder 21 affixed tothe upper end of the reflector 14. It can thus be seen that when thebottom closure member 17 is unlatched and pivoted to its open position,as shown by phantom lines in FIG. 1, both the reflector and refractorremain mounted thereon and pivot downwardly therewith.

Removal of the reflector 14 and the lamp socket 21 from the bottomclosure member '17 is accomplished by unhooking the upper ends of theelongate coil springs 42 from the socket 21. The refractor 15 is removedby pushing outwardly on the lower ends of the springs 38 as 0 viewed inFIG. 2.

For a more detailed description of the luminaire 10, reference is madeto copending application Serial No. 400,143, filed September 29, 1964,now Patent No. 3,283,- 139 and assigned to the assignee of the instantinvention.

While the lamp illustrated in FIG. 1 is of the mercury vapor type, itwill be understood that any conventional lamp having a metallic threadedbase and a center 4. The lampholding means set forth in claim 2 whereinsaid bore extends through said insulating base to expose for view thebase of said lamp.

5. The lampholding means set forth in claim 4 wherein the width of saidinsulating base is substantially less than the height of said threadedlamp base whereby the end of said lamp base extends outwardly throughsaid insulating base to engage said spring contact members.

6. The lampholding means set forth in claim 3 wherein said bore extendsthrough said insulating base and the width of said insulating base issubstantially less than the height of said threaded lamp base wherebythe end of said lamp base extends outwardly through said insulating baseto engage said spring contact members.

7. Lampholding means for use with a lamp having a threaded conductivebase and a central contact mounted on said base and insulated from theconductive portion thereof, said lampholding means including aninsulating base having an internally threaded bore extendingtherethrough for receiving said threaded lamp base through one end, thewidth of said insulating base being substantially less than the heightof said threaded lamp base whereby the end of said lamp base extendsoutwardly through said insulating base, first and second spring contactmembers afiixed in spaced relation to the base of said lampholding meansadjacent the other end of said bore and extending generally inwardlytoward the axis thereof, one of said spring contact members beingrelatively elongate and engaging the central contact when the lamp baseis screwed into said threaded bore, said second spring contact beingrelatively shorter than said first spring contact and having its inneredge disposed adjacent the periphery of said bore and being engageablewith the end of the conductive lamp base, a corner of said second springcontact being bent toward said lamp base to provide a sharp edge in highpressure engagement with said lamp base to prevent said lamp fromloosening in said lampholding means upon vibration.

References Cited by the Examiner UNITED STATES PATENTS 1,733,039 10/1929Weston 33986 2,229,403 1/1941 Benander 339 93 X 2,869,097 1/1959Appleton 339-95 x 3,170,750 2/1965 Appleton 339-95 X EDWARD C. ALLEN,Primary Examiner.

W. DONALD MILLER, Examiner.

1. LAMP HOLDING MEANS FOR USE WITH A LAMP HAVING A THREADED CONDUCTIVEBASE AND A CENTRAL BUTTON CONTACT MOUNTED ON SAID BASE AND INSULATEDFROM THE CONDUCTIVE PORTION THEREOF, SAID LAMPHOLDING MEANS INCLUDING ANINSULATING BASE HAVING A THREADED BORE FOR RECEIVING SAID THREADED LAMPBASE, FIRST AND SECOND SPRING CONTACT MEANS AFFIXED TO SAID BASE ANDEXTENDING INWARDLY TOWARD SAID BORE, ONE OF SAID SPRING CONTACT MEANSENGAGING THE CENTRAL BUTTON CONTACT WHEN THE LAMP BASE IS SCREWED INTOSAID THREADED BORE, SAID SECOND SPRING CONTACT MEANS TERMINATING IN ANINNER EDGE DISPOSED ADJACENT THE PERIPHERY OF SAID THREADED BORE, SAIDINNER EDGE HAVING FIRST AND SECOND PORTIONS, SAID FIRST PORTION HAVING ARELATIVELY LARGE AREA RESILIENTLY ENGAGEABLE WITH THE END OF THECONDUCTIVE BASE OF SAID LAMP TO PROVIDE GOOD ELECTRICAL CONTACTTHEREWITH, SAID SECOND PORTION BEING FLEXIBLE INDEPENDENTLY OF SAIDFIRST PORTION AND HAVING PROJECTING MEANS FORMED THEREON AND EXTENDINGTOWARD SAID LAMP BASE, SAID PROJECTING MEANS HAVING A SHARP EDGE IN HIGHPRESSURE ENGAGEMENT WITH SAID LAMP BASE FOR RESISTING ROTATION OF SAIDLAMP BASE OUTWARDLY OF SAID BORE.